Paul Manafort was sent to jail Friday by a federal judge who said she couldn’t turn a blind eye to claims that he attempted to tamper with witnesses, adding pressure on President Donald Trump’s former campaign manager to cooperate with a U.S. probe of Russian election meddling.

U.S. authorities immediately took Manafort into custody and escorted him out of a packed courtroom, with his wife looking on. The dramatic turn means that Manafort will have to prepare for two federal trials in the coming weeks — one in Washington, and one in Virginia — while confined to a jail cell.

U.S. District Judge Amy Berman Jackson in Washington revoked Manafort’s bail, saying she had no choice but to lock him up because she couldn’t stop him from contacting people.

“This is not middle school,” Jackson said to the lawyers. “I can’t take his cellphone.”

It’s the latest sign of Trump’s deepening legal challenges. Jailing Manafort gives Special Counsel Robert Mueller more leverage as Manafort weighs whether to cooperate and spill any secrets he knows about Trump and the campaign. Confronting possible criminal charges in New York, Trump’s former lawyer Michael Cohen may have a similar choice ahead of him. And on Thursday New York’s attorney general sued the president and members of his family, referring possible tax crimes at Trump’s charitable foundation to the Internal Revenue Service.

Trump has countered with increasingly forceful rhetoric in his attempts to discredit Mueller’s probe and the FBI. He played down Manafort’s importance during a Friday morning press conference on the front lawn of the White House.

“Manafort worked for me for a very short period of time,” Trump said. “I feel badly for some people because they’ve gone back 12 years to find things about somebody. And I don’t think it’s right.”

Later, Trump took to Twitter, writing “Didn’t know Manafort was the head of the Mob.” The president added: “Very unfair!”

Manafort has pleaded not guilty and said he’s done nothing wrong. His lawyers didn’t comment after the hearing.

Manafort faces a trial before Jackson on Sept. 17 and a trial on July 25 in Alexandria, Virginia, on bank- and tax-fraud charges. The judge in Virginia ordered Manafort not to contact witnesses, an admonition that Jackson noted.

“You have abused the trust placed in you six months ago,” said Jackson, noting that she first set bail for him then. Manafort was confined to house arrest and posted a $10 million bond.

‘Marketing Exercise’

While Jackson said she struggled with the decision, she accused Manafort of treating the proceedings as “just another marketing exercise.”

She denied his lawyers’ request to delay his detention while they appeal.

Manafort is accused of failing to register in the U.S. as an agent of Ukraine, and of laundering millions of dollars. Prosecutors say he carried out a lobbying campaign to help pro-Russian President Viktor Yanukovych improve his image in the West. Manafort paid 2 million euros to veteran European politicians, known as the Hapsburg Group, to lobby discreetly, according to the prosecutors. While Manafort claims they only worked in Europe, prosecutors say they also lobbied in the U.S. without registering — a violation of federal law.

At the hearing, prosecutor Greg Andres said that Manafort can’t be trusted to avoid contacting witnesses given he’s already accused of lying to his lawyer and accountants, as well as the IRS and Justice Department.

While out on bail, prosecutors say Manafort tried to contact a pair of former journalists who’d worked on the lobbying, asking them to characterize their work as excluding the U.S.

Andres revealed that one of the witnesses was driving with his wife in rural Italy when Manafort contacted him on Feb. 24, the day after he was indicted on expanded charges in Washington. A lawyer for the witness told prosecutors that Manafort said, “This is Paul, Paul Manafort. I need to give you a heads up about Hapsburg.” Andres said the witness told Manafort that he couldn’t talk and hung up.

‘Random Outreaches’

“These are not random outreaches to these witnesses,” Andres said. “This is a sustained campaign over a five-week period.”

Andres also said that Manafort communicated with several people through the practice of giving them access to unsent emails.

Manafort’s attorney Richard Westling denied during the hearing that his client tampered with any witness. Given the expanding nature of the government’s case, he said, Manafort had “no way of knowing” when the two men became witnesses.

Late Friday, Mueller’s team submitted to the court its plan to tell jurors at Manafort’s trial about past misconduct that may illuminate his motives or intent.

The evidence includes proof he structured a payment to the law firm Skadden, Arps, Slate Meagher & Flom about the fairness of the trial of ex-Ukrainian Prime Minister Yulia Tymoshenko to skirt a Ukrainian public procurement law and that, for tax reasons, in 2014 he claimed a New York City apartment was used for business purposes, then reversed that claim a year later when seeking a loan secured by it.

The Manafort cases are U.S. v. Manafort, 17-cr-201, U.S. District Court, District of Columbia (Washington), and 18-cr-83, U.S. District Court, Eastern District of Virginia (Alexandria).